Infinite dilution activity coefficient and isothermal vapor-liquid equilibrium data have been measured for the binary MTBE+methanol, MTBE+n-heptane, MTBE+2,2,4-trimethylpentane systems at using head space gas chromatography(H.S.G.C). The vapor-liquid equilibria estimated with infinite dilution activity coefficient are in good agreement measured values. These equilibrium data were correlated with the excess Gibbs energy model, and the thermodynamic consistency test was also carried out by the Redlich-Kister equation.

The purpose of this study is to investigate the effect of process condition on the pore size distribution in porous silicon layer prepared by electrochemical reaction. Porous silicon layers formed on p-type silicon wafer show the network structure of fine pores of which diameters are less than . Pore diameters increased up to about by subsequent chemical etching using n-type silicon wafers.

Titania gel() was prepared by the addition of hexylene glycol in sol-gel process. gel after hydrolysis reaction showed rutile phase transformation at low temperature()under air atmosphere in a closed furnace. To promote the decomposition of organic additives incorporated into titania gel structure, packed bed reaction system with oxygen flow was attempted and the rutile phase was found at which is lower than that of closed system. HG incorporation into TEOT was identified by using FT-IR. From the spectra, the bidentate ligand between TEOT and hexylene glycol was identified after hydrolysis reaction as well as before the TEOT hydrolysis reaction. To confirm the effect of bidentate ligand in titania gel, ethylene glycol, acetic acid, ethylenediamine and ethyl acetoacetate were added to TEOT and the rutile transformation was also confirmed at .

PFO(pyrolized fuel oil), which is the bottom oil from a NCC(naphtha cracking center), was initially heat-treated at for 2hr under blowing to remove the volatile matters from the original constituents of the feedstock. The nonvolatile precursor-pitch derived from the PFO raw material was thermally pyrolized in the temperature ranges from to for 3 hr during the second thermal stage under 500cc/min blowing. Spinnable isotropic pitch with the softening point of and the toluene insolubles of 28wt% was obtained at , and then was successfully spun through a 0.5mm capillary sized-spinneret. After spinning, an isotropic carbon fiber of diameter was obtained via oxidation and carbonization procedures. Mesophase spherules began to be observed from the second-stage product pitch pyrolized at , and bulk mesophase with a flow texture was observed at and .

A 100W-class stack consisting of ten molten carbonate fuel cells has been fabricated and tested to establish the basic technology for an internally manifolded stack. Each cell in the stack had an effective electrode area of , and reactant gases were distributed in each cell in a cross-flow configuration. Performance of the stack was investigated as a function of gas utilization, gas composition and temperature using a specially designed stack test apparatus. It was possible to have a stack with an output of more than 100W using an anode gas of and a cathode gas of . The open circuit voltage of the stack was 11.2V and the voltage at a current density of and gas utilization of 0.4 was 7.3V. The voltage loss due to the internal resistance and the electrode polarization, however, was higher than that of a single cell, and the distribution of cell voltages was not uniform indicating that differences in stacking and operating environment of each cell have to be minimized to enhance the cell performance and uniformity. Since the performance degradation of the stack during the continuous operation at was higher than that of the single cell, further works are required to enhance the life of the stack.

Alumina composite membranes were manufactured using coating sols witch were synthesized through sol-gel method. The AlOOH sol, prepared with the Yoldas method, appeared the most transparent and contained the smallest. particles when the HCl/alkoxide molar ratio was 0.07. The same sol resulted in the unsupported -alumina membrane with the largest surface area. -Alumina layers with small pores were formed on top of the -alumina supports with larger pores by repeating the coating-drying-calcining cycle with AlOOH sols. Dip coating, vacuum coating and pump coating methods were applied and at least 3 coating-drying-calcining cycles were necessary with 0.8 M sols. Crack formation or peeling of coating layers were frequently observed when repeated coating-drying cycles were followed by final calcining or concentrated sols were used. Surfaces of alumina composite membranes could be modified with silica or CaO. Distribution of dopant could be controlled by changing the solutions.

The effect of temperature on the particle entrainment rate was measured and discussed in a gas fluidized bed(0.1m in diameter, 2.1m high) which used sand as a bed material and was equipped with an electric heater. The particle size(0.075-0.425mm). gas velocity(0.65-2.3m/s) and bed temperature() were varied as experimental variables. The particle entrainment rate increased very slowly with the bed temperature at the gas velocity less than 0.8m/s. At the gas velocity greater than 1m/s, the particle entrainment rate decreased with increasing the bed temperature until a certain temperature above which the particle entrainment rate increased with the bed temperature. The minimum point of particle entrainment rate shifted to higher temperature with increasing gas velocity. The change of the particle entrainment rate along the bed temperature was same as that of the particle size whose terminal velocity was equal to the gas velocity.

Regeneration of an industrial incineration catalyst was studied with respect to the changes in catalyst characteristics and the recovery of incineration activity. The incineration catalyst was characterized as platinum dispersed on cordierite support, and catalyst deactivation was due to the deposition of foulants as well as sulfur impurities. The ex-situ, liquid-environment regeneration procedures consisting of cleaning in alkaline solution followed by neutralization in acid solution resulted in not only removal of foulants and sulfur species from the deactivated catalyst, but alteration of pore structure of the catalyst support. The activity of regenerated catalyst, measured by means of CO oxidation reaction, depended on the regeneration conditions. The increases in concentration and temperature of alkaline cleaning solution as well as cleaning time brought about the increase in the incineration activity of regenerated catalyst.

The rate of dehydrogenation of-2propanol was obtained using a differential flow reactor over ruthenium catalysts supported on alumina and activated carbon. The reaction rate was derived as , which was calculated on gas phase and liquid phase reactions. In order to consider the effect of reaction temperature, was assumed. The equilibrium constant, , of acetone adsorption was assumed to be constant because the variation was small over the narrow temperature range. The reaction rate of gas phase was faster than that of liquid phase, and it was decreased as the concentration of acetone increased. The rate equation could express the effect of temperature and acetone concentration on 2-propanol dehydrogenation reaction.

Enzymatic hydrolysis of lignocellulosic biomass by various commercial enzymes has been studied. The commercial cellulases used in this study showed different CMCase and -glucosidase activities but have similar FPase activities. CMCase was found to play a key role for the enzymatic hydrolysis of lignocellulosic biomass which contains inert material such as hemicellulose and lignin. The -glucosidase inhibition by lignin was the most remarkable for Celluclast which has the lowest -glucosidase activity. FPase activity could not represent the capability to hydrolyze the lignocellulosic biomass.

A performance modeling of phosphoric acid fuel cell was constructed using error back-propagation neural network with generalized delta rule. The network was trained to produce the performance curve according to cell temperatures, flow rates and flow rates. The reliability of performance prediction was verified by comparing the experimental data of unit cell. The three layered error back-propagation net-work learned exactly the performance curve of unit cell when the step size coefficient was 0.7 and the momentum was 0.9. It offered reasonable prediction for various and flow rates and temperatures. This neural network combined to commercial process simulator ASPEN PLUS as a unit for fuel cell stack. In this process simulation, 50kW PAFC system was selected, and the effects of operating variables on the performance of the system were also investigated. The maximum power of fuel cell was achieved when the reformer temperature was at 1 atm, and steam-carbon ratio was 2.6. It is proper to maintain the operating temperature of fuel cell at .

Adsorption experiments for and their mixtures on activated carbon were performed by static volumetric method. From the parameters obtained from single component adsorption isotherm, multicomponent adsorption equilibria could be predicted and compared with experimental data. Among coupled Langmuir isotherm, coupled Langmuir-Freundlich isotherm, IAST and F-H VST, coupled Langmuir-Freundlich isotherm showed the best agreement with the experimental results for binary and ternary adsorption equilibria of on activated carbon.

Characteristics of unsteady state behavior and fluctuations of fluidized particles have been investigated by adopting the stochastic method in a three-phase fluidized bed of 0.152m ID and 2.5m in height. Air, water and glass beads whose density is and diameter is in the range of have been used as gas, liquid and solid phase, respectively. The mean fraction, mean residence time and fluctuating frequency of fluidized particles in the test section, and the exiting rate of the particles from the test section have been obtained. The exiting rate of the particles has decreased exponentially with time lag during the relaxation of the bed, and the mean residence time of the particles in the test section has decreased with an increment of the gas velocity. The fluctuating frequency of particles has increased with an increment of the gas velocity and particle size, but it has attained its maximum value with an increment an increment of the gas velocity and particle size, but it has attained its maximum value with an increment of the liquid velocity and bed porosity. The particle fluctuating frequency has been well correlated in terms of dimensionless particle size and dimensionless fluid velocity based on the isotropic turbulence theory.

The effect of process variables on the physical properties of the anode was investigated to optimize the fabrication process of the Ni+10 w/o Cr anode for molten carbonate fuel cells and it was found that the desired characteristics of the anode such as pore size and porosity could be obtained through the change of the ball mill time, the firing temperature, and the firing atmosphere, but not through the change of the binder amount. When the ball mill time was 48 hours and the firing temperature was over , the anode with the mean pore size of and the porosity of 50-60% could be fabricated. This was possible only when the green sheet of the anode was fired under either the oxidation-reduction atmosphere or the reduction atmosphere of 99.5% which has oxidized Cr to sintering-resistant . Under the reduction atmosphere of 99.9999% the solid solution amount of Cr in Ni increased, but sintering of Ni particles could not be hindered due to no formation of , resulting in the porosity of 42% which was too low for anodes.

Measured process data are usually containing random errors and gross errors. These measured data do not satisfy process constraints such as the mass and energy balances that describe a process. For the use of these error-contained data in process analysis and optimization, the preprocessing steps such as gross error identification and elimination, and data reconciliation(data rectification)are prerequisite. The existing methods are based on mathematical and statistical techniques, but recently neural networks were investigated for data rectification. In this study, autoassociative neural networks(AAN) and robust ANN(RAAN) were applied for the data rectification of process data of CSTR. The performance of RAAN proved to be superior to that of AAN in the data rectification. we conclude that the use of AAN and RAAN appears to be a promising tool data rectification.